JP6264154B2 - Calorimeter and calorie measuring method - Google Patents

Description

  The present invention relates to a calorimeter and a calorific value measuring method for measuring fluctuations in the calorific value of steam flowing in a pipe.

  In facilities such as factories, the equipment may be operated by steam generated by, for example, a boiler. At this time, the steam generated in the boiler or the like is supplied to the equipment through the piping. As a method for measuring the heat quantity of steam in the pipe, for example, the input energy measuring method disclosed in Patent Document 1 can be cited. In the method of measuring input energy of Patent Document 1, the temperature of steam flowing into the equipment is measured, the temperature of the steam return water coming out of the equipment is measured, and the flow rate of the steam return water is obtained by an ultrasonic flowmeter. Then, the steam energy input to the equipment is obtained by subtracting the outlet steam enthalpy from the inlet steam enthalpy and multiplying the result by the flow rate of the steam return water.

  In measuring the amount of heat as described above, it is difficult to measure the flow rate of the fluid in the pipe. In Patent Document 1, as a well-known method, the flow rate in the pipe is obtained by an ultrasonic flowmeter.

  Further, as a method for measuring the flow rate in the pipe, for example, there are flow rate measuring devices disclosed in Non-Patent Document 1 and Patent Document 2. In Non-Patent Document 1, the flow rate and flow rate of a fluid are calculated by heating the outer surface of a pipe with a heater and measuring the temperature change generated in the heater. It is stated that the amount of heat taken away by the fluid has a certain correlation with the flow velocity of the fluid, and thus the higher the flow velocity, the lower the temperature of the heater. According to Non-Patent Document 1, this configuration makes it possible to reduce the cost as compared with the case where an ultrasonic flowmeter is used as in Patent Document 1.

Patent No. 4694185 JP 2013-205310 A

New weapon for energy saving Commercialization of piping surface installation type simple calorimeter, Takasago Thermal Engineering Co., Ltd. website, [Search on March 27, 2014], Internet <URL: http: //www.tte- net.co.jp/corporate/pressrelease/20140117.html>

  It is considered that the flow rate measuring devices of Non-Patent Document 1 and Patent Document 2 can be suitably used for piping through which relatively low-temperature cold / hot water flows. However, when the fluid flowing through the pipe is steam, the heater must apply heat at a temperature that exceeds the temperature of the steam (saturated steam or superheated steam). Since the heat of the heater needs to be taken away by the fluid in the pipe, the outside of the heater needs to be covered with a heat insulating material. However, if heat is applied at a temperature exceeding the temperature of the steam, the heat insulating material may be damaged. For this reason, it is difficult to apply the calorimeter of Non-Patent Document 1 to piping through which steam flows. Further, even if the heat insulating material is a material that can withstand high temperatures, a high-output power source, that is, a system power source is required to bring the heater to such a high temperature. Then, the calorimeter of nonpatent literature 1 cannot be used in the field where a fire is strictly prohibited, such as equipment which handles a flammable thing.

  In view of such problems, the present invention has an object to provide a calorimeter and a calorific value measuring method that can be applied to piping through which steam flows and that can be suitably used in explosion-proof equipment. .

  In order to solve the above problems, a typical configuration of a calorimeter according to the present invention is a calorimeter that measures fluctuations in the calorific value of steam flowing in a pipe, and measures the temperature of steam at the center of the pipe. 1 temperature sensor, a cooling device that cools the surface of the pipe downstream from the first temperature sensor, a heat flux sensor that is arranged at the same position as the cooling device and measures a heat flux that flows out of the surface of the pipe, and a cooling device A second temperature sensor that is arranged at the same position and measures the surface temperature of the pipe, and a difference in temperature measured by the first temperature sensor and the second temperature sensor and a fluctuation in the amount of heat of the steam flowing in the pipe are calculated from the heat flux. And a calculating unit.

  In the said structure, the surface of piping is cooled with a cooling device, the flow rate of steam is measured using the heat flux which flows out out of the surface of piping by being cooled, and the calorie | heat amount of steam is measured using this. In other words, while heat is conventionally used to heat the pipe and is taken away, in the present invention, the pipe is cooled to form a temperature gradient, and the flow rate is measured using heat flux. In Non-Patent Document 1, overheating is sensible heat and changes in temperature. However, in the present invention, condensation occurs when the steam is cooled, and thus condensing heat transfer. By cooling the piping and measuring the flow velocity in this way, it is not necessary to apply heat that exceeds the temperature of the steam as in the prior art, and therefore, the present invention can be suitably applied to piping through which steam flows. Also, unlike the case of heating the surface of the pipe, a high output power source is not necessary for cooling. For this reason, if it is a calorimeter of this invention, it can be safely used by using the battery incorporated also in an explosion-proof installation.

  The first temperature sensor may be attached to the surface of the pipe and covered with a heat insulating material. Thereby, since the heat radiation around the first temperature sensor is suppressed, the surface temperature of the pipe can be regarded as the temperature of the central part of the pipe.

  The first temperature sensor may be attached to a metal bar welded to a metal plate in surface contact with the surface of the pipe. Thereby, it is possible to accurately measure the surface temperature of the pipe in the first temperature sensor while facilitating the mounting of the first temperature sensor.

  In order to solve the above problems, a representative configuration of the calorific value measuring method according to the present invention is a calorific value measuring method for measuring a variation in the calorific value of steam flowing in a pipe, and measures the temperature of steam at the center of the pipe. Cool the pipe surface downstream of the temperature measurement point, measure the heat flux flowing out from the pipe surface and the pipe surface temperature at the same position as the cooling point, and measure the measured steam temperature and pipe temperature. It is characterized in that the fluctuation of the amount of heat of the steam flowing in the pipe is calculated from the temperature difference from the surface temperature and the heat flux. The above-described components based on the technical idea of the calorimeter and the description thereof can be applied to the calorific value measurement method.

  ADVANTAGE OF THE INVENTION According to this invention, the calorimeter and the calorie | heat amount measuring method which can be applied also to piping through which steam flows, and can be used suitably also in an explosion-proof installation can be provided.

It is a figure which illustrates the facility which applies the calorimeter and calorie | heat amount measuring method concerning this embodiment. It is a figure which illustrates the calorimeter concerning this embodiment. It is sectional drawing explaining the attachment to the steam piping of the 1st temperature sensor shown in FIG. It is detail drawing of the cooling device shown in FIG. It is a figure explaining the measurement principle of a heat flux.

  FIG. 1 is a diagram illustrating a facility 200 to which a calorimeter and a calorific value measuring method according to the present embodiment are applied. The dimensions, materials, and other specific numerical values shown in the following embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified.

  In the facility 200 illustrated in FIG. 1, steam is generated by the boiler 202, and the generated steam is supplied to the production facilities 202 a and 202 b through the steam pipe 210. In the present embodiment, the boiler 202 is illustrated as the steam generation facility, and the production facilities 202a and 202b are illustrated as the facility to which the steam is supplied. However, the present invention is not limited thereto, and the steam piping 210 through which the steam flows is provided. As long as it is equipment, the calorimeter and the calorific value measuring method according to the present embodiment can be applied to other equipment.

  FIG. 2 is a diagram illustrating the calorimeter 100 according to this embodiment, and schematically shows the calorimeter 100. 3 is a cross-sectional view for explaining the attachment of the first temperature sensor 110 shown in FIG. 2 to the steam pipe 210, and shows a cross-section at the position AA in FIG. FIG. 4 is a detailed view of the cooling device 120 shown in FIG. Hereinafter, the calorimeter 100 according to the present embodiment will be described together with the calorimeter 100 shown in FIGS. 2, 3 and 4 in detail. In FIG. 3, the heat insulating material 116 shown in FIG. 2 is not shown for convenience of explanation.

  The calorimeter 100 shown in FIG. 2 measures the fluctuation | variation of the calorie | heat amount of the steam which flows through the inside of piping (steam piping 210). As shown in FIG. 2, the calorimeter 100 of the present embodiment includes a first temperature sensor 110, a second temperature sensor (not shown), a cooling device 120, a heat flux sensor 130 (see FIG. 4), and a calculation unit 140. Consists of.

  The first temperature sensor 110 measures the temperature of the steam at the center of the steam pipe 210. As shown in FIG. 3C, in the present embodiment, the first temperature sensor 110 is attached to a metal rod 114 welded to a metal plate 112 that is in surface contact with the surface of the steam pipe 210. Thereby, the first temperature sensor 110 can be easily attached to the steam pipe 210 via the metal plate 112 and the metal rod 114 by winding the metal plate 112 around the steam pipe 210. Since the metal plate 112 and the metal rod 114 are excellent in thermal conductivity, the heat transferred to them is suitably transmitted to the first temperature sensor 110. Accordingly, it is possible to accurately measure the temperature of the steam pipe 210 while facilitating the mounting of the first temperature sensor 110.

  When the first temperature sensor 110 is attached to the steam pipe 210, as shown in FIG. 3A, first, the metal plate 112 to which the first temperature sensor 110 is attached is covered with the outer surface (surface) of the steam pipe 210. To place. One end 112a of the metal plate 112 has a bent tab shape, and an insertion hole 112b is formed in the end 112a. When the metal plate 112 is wound around the steam pipe 210 as shown in FIG. 3A, 118 is wound around the outer side of the metal plate 112 as shown in FIG. It passes through the insertion hole 112b. Then, the metal plate 112 is wound around the steam pipe 210 as shown in FIG. 3C by inserting the end portion 118a into the fastening portion 118b of the fastening band 118 and fastening the fastening band 118.

  That is, in the present embodiment, the first temperature sensor 110 is fixed to the steam pipe 210 by winding the metal plate 112 around the steam pipe 210 and tightening it with the fastening band 118. According to such a configuration, it is possible to cope with various pipe diameters without preparing individual metal plates corresponding to the pipe diameter of the steam pipe 210.

  As shown in FIG. 2, in the present embodiment, the first temperature sensor 110 is attached to the surface of the steam pipe 210 and is covered with a heat insulating material 116. Thereby, since heat dissipation around the first temperature sensor 110 is suppressed, the surface temperature of the steam pipe 210 can be regarded as the temperature of the central portion of the steam pipe 210.

  Further, in this embodiment, after the steam pipe 210 is covered with the heat insulating material 116, the heat insulating material 116 is further tightened by the fastening bands 102a and 102b. Thereby, the 1st temperature sensor 110 can be fixed more favorably, and it becomes possible to heighten the thermal insulation effect by the thermal insulation material 116. In the present embodiment, the entire steam pipe 210 is covered with the heat insulating material 116 as shown in FIG. 2, but the present invention is not limited to this, and only the periphery of the first temperature sensor 110 is covered with the heat insulating material 116. It is good also as composition to do.

  The cooling device 120 cools the surface of the steam pipe 210 on the downstream side of the first temperature sensor 110. As shown in FIG. 4A, the cooling device 120 of the present embodiment is configured by mounting parts 120a and 120b divided into two parts. The mounting portions 120a and 120b include contact portions 122a and 122b, respectively, and heat sinks 124a, 124b, 124c, 124d, 124e, and 124f are provided on the outer surfaces of the contact portions 122a and 122b, respectively. Fans 126a, 126b, 126c, and 126d are arranged outside the heat sinks 124a to 124f.

  The contact parts 122a and 122b shown in FIG. 4A are brought into contact with the steam pipe 210 (not shown in FIG. 4) so as to face each other, and the snaps 128c and 128d of the mounting part 120b are brought into contact with the engaging parts 128a and 128b of the mounting part 120a. Is engaged, the cooling device 120 is in the state shown in FIG. Thereby, in the cooling device 120 of the present embodiment, the heat of the surface of the steam pipe 210 is radiated by the heat sinks 124a to 124f through the contact portions 122a and 122b, and the heat dissipation of the heat sinks 124a to 124f is promoted by the fans 126a to 126d. Is done. That is, in the present embodiment, the surface of the steam pipe 210 is cooled by the heat sinks 124a to 124f and the fans 126a to 126d constituting the cooling device 120.

  In particular, as in the present embodiment, the mounting portions 120a and 120b are engaged by the engaging portions 128a and 128b and the snaps 128c and 128d, so that they can be fixed while being in close contact with the steam pipe 210. Therefore, the heat of the steam pipe 210 can be more efficiently transmitted to the contact portions 122a and 122b and thus the heat sinks 124a to 124f. Further, when the surface of the steam pipe 210 is rough, a heat transfer sheet (not shown) may be interposed between the surface of the steam pipe 210 and the surface of the contact portions 122a and 122b that are in contact with the steam pipe 210. Thereby, the close_contact | adherence degree of the surface of the steam piping 210 and contact part 122a * 122b can be raised, and it becomes possible to raise a heat transfer rate. Note that the number of heat sinks and fans in the cooling device 120 of the present embodiment is merely an example, and can be changed as appropriate.

  Moreover, as shown to Fig.4 (a), the heat flux sensor 130 is arrange | positioned in the surface which contacts the steam piping 210 of the contact part 122b. The heat flux sensor 130 is disposed at the same position as the cooling device 120 and measures the heat flux flowing out from the surface of the steam pipe 210 when cooled by the cooling device 120. In the present embodiment, the heat flux sensor 130 also functions as a second temperature sensor that is disposed at the same position as the cooling device 120 and measures the surface temperature of the steam pipe 210. That is, the second temperature sensor is built in the heat flux sensor 130 of the present embodiment.

  In the present embodiment, the configuration in which the heat flux sensor 130 and the second temperature sensor are integrated is illustrated, but the present invention is not limited to this, and it is naturally possible to make them separate. In that case, in the cooling device 120 shown in FIG. 4, it is preferable to arrange | position a 2nd temperature sensor between the steam piping 210 and contact part 122a * 122b.

  Further, in the steam pipe 210, the mounting location of the cooling device 120 described above is a vertical portion or horizontal portion of the piping, that is, a straight pipe portion, and the length of the straight pipe portion before and after the mounting location is 20 times or more of the pipe diameter. It is preferable that Thus, when the steam is cooled by the cooling device 120, it is possible to suppress the generation of turbulent flow and to suitably generate a two-phase flow of steam. In addition, when attaching the cooling device 120 to the horizontal part of the steam pipe 210, it is preferable to install the heat flux sensor 130 so as to face the upper surface of the steam pipe 210. This makes it possible to prevent water droplets from adhering to the heat flux sensor 130 when the steam is condensed.

  The first temperature sensor 110 shown in FIG. 2 and the heat flux sensor 130 shown in FIG. 4A are connected to the calculation unit 140, respectively. The calculation unit 140 determines the steam pipe from the steam temperature measured by the first temperature sensor 110, the surface temperature of the steam pipe 210 measured by the second sensor (not shown), and the heat flux measured by the heat flux sensor 130. Fluctuations in the amount of heat of the steam flowing through 210 are calculated.

  FIG. 5 is a diagram for explaining the heat flux measurement principle. As shown in FIG. 5, the steam flowing in the steam pipe 210 has a temperature distribution and a speed distribution, a temperature boundary layer in which the temperature changes in the fluid in contact with the inner surface of the steam pipe 210, and a speed boundary in which the speed changes. A layer is produced. The velocity boundary layer and the temperature boundary layer become thinner as the vapor flow rate increases. And since a thermal gradient becomes large as a temperature boundary layer becomes thin, the surface temperature of the steam piping 210 rises, and a heat flux increases with the rise. Therefore, the flow velocity of the steam flowing through the steam pipe 210 can be calculated from the heat flux measured by the heat flux sensor 130.

Specifically, when the surface temperature of the steam pipe 210 at the cooling spot (the place where the cooling device 120 is installed) is Tw, the temperature of the steam flowing through the steam pipe 210 is Tf, and the heat flux q is the relationship between them. Is represented by equation (1). H in Formula (1) is a heat transfer coefficient. Therefore, the heat transfer coefficient h can be calculated by measuring the surface temperature Tw of the steam pipe 210, the temperature Tf of the steam flowing through the steam pipe 210, and the heat flux q.
q = h (Tf? Tw) Equation (1)

When steam (fluid) flows in the steam pipe 210 as in this embodiment, forced convection occurs between them. The heat transfer coefficient h at this time is represented by the following formula 2. Nu in Equation 2 is the Nusselt number, and ri is the inner diameter of the steam pipe 210. λw is the thermal conductivity of the fluid, and is determined by the type of fluid and the temperature of the fluid. Therefore, the Nusselt number Nu can be calculated by substituting the heat transfer coefficient h calculated by the equation (1) into the equation (2).
h = Nu × λw / ri Equation (2)

In turbulent flow with Reynolds number Re> 10,000, Nusselt number Nu is expressed as a function of Reynolds number Re and Prandtl number Pr, as shown in equation (3). The Prandtl number Pr is determined by the type of fluid and the temperature of the fluid. x is the distance from the leading edge of the flat plate or the quality of the vapor in a two-phase flow, P is the pressure and P _cr is the critical pressure.
Therefore, the Reynolds number Re can be calculated by substituting the Nusselt number Nu calculated by the equation (2) into the condensation heat transfer equation (3).
Nu = f (Re, Pr)
= 0.023Re ^0.8 Pr ^0.4 [(1-x) ^0.8 + 3.8x ^0.76 × (1-x) ^0.04 / (P / P _cr ) ^0.38 ] Equation (3)

The relationship between Reynolds Re and flow velocity V calculated by the above equation (3) is as shown in equation (4). In this equation (4), the kinematic viscosity coefficient ν is determined by the type of fluid and the temperature of the fluid. Therefore, by substituting Reynolds Re calculated in Expression (3) into Expression (4), the flow velocity of the steam flowing through the steam pipe 210 is calculated.
Re = V × ri / ν (4)

  When the steam flow velocity is calculated by the above-described equations (1) to (4), the flow rate per unit time of the steam can be calculated by multiplying the flow velocity by the cross-sectional area in the steam pipe 210. Then, by multiplying the steam flow rate per unit time by the latent heat of steam, it is possible to calculate the amount of steam heat per unit time, so that the variation can be calculated by comparing the amount of heat per unit time. it can.

  As described above, according to the calorimeter 100 and the calorie measuring method according to the present embodiment, the steam flow velocity is calculated using the heat flux that flows out of the surface of the steam pipe 210 when cooled by the cooling device 120. It is possible to measure the amount of heat of steam using the flow rate. By using the heat flux at the time of cooling of the steam pipe 210 as in the present embodiment, it is not necessary to apply heat that exceeds the temperature of the steam, so that it can be suitably applied to pipes through which steam flows. Become. Further, the steam pipe 210 may be cooled by power enough to drive a fan, and a high-output power source is not required for heating the pipe surface. Therefore, the calorimeter 100 according to the present embodiment can be sufficiently driven by a battery, and can be used safely even in an explosion-proof facility that requires attention to fire.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used as a heat exchanger and a humidifier for adjusting the temperature of indoor air.

DESCRIPTION OF SYMBOLS 100 ... Calorimeter, 102a * 102b ... Fastening band, 110 ... 1st temperature sensor, 112 ... Metal plate, 112a ... End part, 112b ... Insertion hole, 114 ... Metal rod, 116 ... Thermal insulation material, 118 ... Fastening band, 118a ... End part, 118b ... Fastening part, 120 ... Cooling device, 120a ... Mounting part, 120b ... Mounting part, 122a ... Contact part, 122b ... Contact part, 124a ... Heat sink, 124b ... Heat sink, 124c ... Heat sink, 124d ... Heat sink, 124e ... heat sink, 124f ... heat sink, 126a ... fan, 126b ... fan, 126c ... fan, 126d ... fan, 128a ... engagement part, 128b ... engagement part, 128c ... hook, 128d ... hook, 130 ... heat flux sensor, 140 ... calculation unit, 200 ... facility, 202 ... boiler, 202a ... raw Equipment, 202b ... production equipment, 210 ... steam pipe

Claims (4)

A calorimeter that measures fluctuations in the amount of heat of steam flowing in a pipe,
A first temperature sensor for measuring the temperature of the steam at the center of the pipe;
A cooling device for cooling the surface of the pipe on the downstream side of the first temperature sensor;
A heat flux sensor arranged at the same position as the cooling device and measuring a heat flux flowing out from the surface of the pipe;
A second temperature sensor arranged at the same position as the cooling device and measuring the surface temperature of the pipe;
A calculation unit that calculates a variation in the amount of heat of the steam flowing in the pipe from the difference in temperature and the heat flux measured in the first temperature sensor and the second temperature sensor;
A calorimeter comprising:   The calorimeter according to claim 1, wherein the first temperature sensor is attached to a surface of the pipe and is covered with a heat insulating material.   The calorimeter according to claim 1 or 2, wherein the first temperature sensor is attached to a metal bar welded to a metal plate that is in surface contact with the surface of the pipe. A calorific value measuring method for measuring fluctuations in the calorific value of steam flowing in a pipe,
Measure the steam temperature in the center of the pipe,
Cooling the surface of the pipe on the downstream side of the temperature measurement point,
Measure the heat flux flowing out from the surface of the pipe at the same position as the cooling point and the surface temperature of the pipe,
A calorific value measuring method, comprising: calculating a variation in the calorific value of the steam flowing in the pipe from the temperature difference between the measured steam temperature and the surface temperature of the pipe and the heat flux.

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